If the 12PF capacitance value of the reference circuit is changed to 7pF, will it affect the operation of the crystal oscillator circuit?

[Wwing]

Dear team：

    If the 12PF capacitance value of the reference circuit is changed to 7pF, will it affect the operation of the crystal oscillator circuit?

[Kaja]

Hi, 

do you mean if the load capacitance, CL, changes from 12 pF to 7 pF?

If so, yes then you need to change the load capacitors, Ccap. Ccap = CL*2 - 4 pF. 

Best regards,
Kaja

[Wwing]

Hi, 

  If I dont change the load capacitor, will it affect the operation of the crystaloscillator circuit?

[Wwing]

Hi team：

  I also have another question,so the oscillator manufacturer suggessed me to use 7pF, load capacitor. but I used the reference circuit 12pF.Will something go wrong? XTAL 32.768KHz

[Kaja]

So if you have a CL = 7 pF, for the 32.768 kHz crystal, you should have load capacitors = 10 or 9 pF. 
You set the accuracy of of the crystal oscillator, and not having the right load capacitors will give you less accuracy. See clock control. 

Best regards,
Kaja